The word G. porogwil appeared in the Gnomish Lexicon of the 1910s as a combination of G. porog “fowl (domestic)” and G. uil “hen” (GL/64, 74).
Neo-Sindarin: I would adapt this word as ᴺS. porochuil for purposes of Neo-Sindarin, updating the second element to the neologism ᴺS. huil “hen”. The longer form is better distinguished from ᴺS. huil “bitch, female dog”.
The word G. uil “hen” appeared in the Gnomish Lexicon of the 1910s (GL/74), almost certainly a cognate of ᴱQ. oi “bird, hen” which Tolkien considered deriving from ᴱ√OHO “cry” (QL/69). In Common Eldarin: Noun Structure from the early 1950s, Tolkien had the primitive word ✶kholjē “hen” derived from the root √KHOL “crow, cry aloud” (PE21/82), which may be a later iteration of this Gnomish uil “hen” word.
Neo-Sindarin: Based on the above, Gábor Lőrinczi proposed a neologism ᴺS. hŷl “hen” as recorded in the VQP (VQP). However, my analysis of Sindarin phonology indicates that ᴺS. huil is the more likely result ✶kholjē: compare thuil and thuin plurals of thôn and thôl, and possibly also ruin < ✱runyā and fuir < ✱forya. For further details see the entry on how [[s|final [i] intruded into preceding syllable]] in Sindarin.
In any case, I recommend ᴺS. huil for “hen” in Neo-Sindarin, or its more elaborate form ᴺS. porochuil.